1. Field of the Invention
The present invention relates to an endoscope sucking operation apparatus, and more particularly to a configuration of a sucking operation apparatus that moves a piston body from a valve portion to open a suction duct (conduit) by performing a pushing operation with respect to a suction button provided to an operating portion.
2. Description of the Related Art
FIG. 5 shows a configuration of a conventional endoscope apparatus, an endoscope has, e.g., a distal end portion 1A including an objective optical system, a solid-state image sensing device, and others, an operating portion 1B provided through a bending portion, and others, a forceps opening (a treatment instrument insertion channel introduction opening) 3 is provided in this operating portion 1B, and a treatment instrument insertion channel 4 is arranged to extend from this forceps opening 3 to a distal end surface of the distal end portion 1A. A suction tube (a duct) 5 through which a fluid (contents) or the like in an observation target is sucked is connected with this treatment instruction insertion channel 4 so that the treatment instrument insertion channel 4 can also function as a suction duct. Further, a suction button 7 is arranged on the operating portion 1B, and a suction pump 9 is connected to the suction tube 5 through a liquid storage tank 8.
FIGS. 6A and B show a configuration of a sucking operation apparatus including the suction button 7, and this example is suggested for a portable endoscope. As shown in the drawings, in this sucking operation apparatus, a piston body 11 is integrally disposed at the center of the suction button 7 formed of an elastic body, and this piston body 11 is arranged to move up and down through a circular inner path 12a of a support main body 12. The suction button 7 can upwardly urge the piston body 11 by using its elastic force, and an opening portion 7a is provided in its side surface. The piston body 11 has an inner path 11a and openings 11b and 11c, and a valve portion 13 that closes the suction duct when the piston body 11 is appressed against a path inner wall of the support main body 12 is provided to the piston body 11 and the support main body 12. It is to be noted that the suction tube 5 on the endoscope distal end side is connected to the lower side of the inner path 12a of the support main body 12 and a suction connecting tube 5D that is used to connect the tank-side suction tube 5 is formed on a side surface of the support main body 12.
According to such a sucking operation apparatus for an endoscope, when a sucking operation is not performed as shown in FIG. 6A, air is sucked from the opening 7a of the suction button 7 based on the suction of the suction pump 9, and the valve portion 13 is closed, and hence suction is not performed from the distal-end-side suction tube 5. On the other hand, when the suction button 7 is pressed, since the piston body 11 moves down and the valve portion 13 and the opening 11c are opened, a liquid (contents) or the like of an observation target is sucked through the treatment instruction insertion channel 4 and the suction tube 5 by a sucking operation of the suction pump 9, and this liquid or the like is discharged to the storage tank 8.
However, in the conventional endoscope sucking operation apparatus, as shown in FIG. 6B, a path between the piston body 11 and the support main body 12 in the valve portion 13 is narrow, and a fluid or the like having less viscosity can be sufficiently sucked, but there occurs a problem that the narrow path in this valve portion 13 may be clogged when sucking a material having high viscosity such as phlegm. That is, in the valve portion 13, the piston body 11 itself (a shaft) remains in a path of a valve receiving portion 13F (a receiving portion of a valve moving portion 13M of the piston body 11) of the support main body 12 even when the valve portion 13 is opened, and the suction duct through which the fluid passes is narrowed due to presence of this piston body 11.
In view of the above-described problem, it is an object of the present invention to provide the endoscope sucking operation apparatus that can readily suck, e.g., a fluid having high viscosity without narrowing the path between the piston body and the support main body in the valve portion of the suction duct.